表面照射下激光与生物组织的光热作用分析  

Optical-thermal Interaction of Biological Tissue Subjected to the Surface-applied Laser Irradiation

作　　者：江世臣[1] 张学学[1] 

机构地区：[1]清华大学热能工程系热能动力工程与热科学重点实验室,北京100084

出　　处：《光电子．激光》2005年第6期752-756,共5页Journal of Optoelectronics·Laser

基　　金：国家自然科学基金资助项目(50276032)

摘　　要：建立了表面照射下激光与生物组织光热作用的二维变物性数学模型,采用MonteCarlo模拟方法数值求解了表面照射下组织内激光能量的分布,进而采用有限差分方法数值求解Pennes生物传热方程得到了组织内的温度分布。计算结果表明:假设组织热物性为常数,将高估组织的温升;假设激光能量在组织内按指数规律衰减,计算得到的光束范围内的组织温升高于采用MOnteCarlo方法的模拟结果;在功率相同的情况下,光束半径越大,光束范围内组织的温升越小,径向温升区域越大。A two-dimensional mathematical model was developed to simulate the photo-thermal interaction of biological tissue subjected to the surface-applied laser irradiation. Laser energy deposition in biological tissue was simulated using Monte Carlo method and temperature distributions in tissue were then numerically calculated using finite difference method based on the Pennes bioheat equation. The numerical results show that the temperature increase will be overestimated if thermal properties of tissue are assumed to be constant as most current researchers take. Moreover when laser energy deposition is assumed to be the specific exponential function temperature increase in tissue near the light spot is much higher than the corresponding value when Monte Carlo method is used to simulate laser energy transport. Under the same operating conditions, the tissue temperature increase near light spot becomes smaller and influenced region where tissue temperature increases perceptibly becomes larger with the 1/e2 radius of laser beam increases.

关 键 词：生物组织 作用分析 照射 表面 CARLO方法 光热 生物传热方程 有限差分方法 激光能量 数值求解 数学模型 模拟方法 温度分布 计算结果 指数规律 模拟结果 变物性 热作用 热物性 温升高 束半径 假设 光束 常数 

分 类 号：O484[理学—固体物理] Q631[理学—物理]